The present invention relates to odor scrubbers for sewage systems, and more particularly to a hydrogen sulfide/mercaptan scrubber adapted for a waste disposal tank and to a method of eliminating hydrogen sulfide and mercaptans from a waste disposal tank.
Disposal of waste can be a problem, especially for those who use a simple waste holding tank, such as typically found in a boat, recreational vehicle and domestic septic systems. Such tanks can produce disagreeable odors under anaerobic conditions. Hydrogen sulfide producing bacteria thrive under anaerobic conditions. The smell of the hydrogen sulfide can be detected at concentrations as low as 0.0011 mg/liter, is particularly obnoxious, and can make the confined interior space of a small vehicle less than a desirable place to be. Mercaptans (sulfur-containing compounds of the form RSH) also create a significant odor problem.
Various commercial waste disposal treatment systems which treat odors are available, but none has been found suitable for a simple waste holding tank, such as found in small pleasure boats, RVS, etc., due to cost, size, complexity, and the like. For example, some systems require a constant source of electrical power which is not found in most pleasure vehicles, or not used due to cost. Most pleasure vehicles have very limited power, and it is desirable that any odor treatment system function efficiently with no outside power source while the vehicle is unattended. Simpler odor treatments are also available, but most are additives which rely on one or more toxic chemicals which cannot be safely pumped into municipal systems. Further, it is desirable that the system require very low maintenance and avoid damage to other components of the waste disposal system.
Accordingly, it is an object of the present invention to provide a novel odor scrubber and method which is adaptable for simple waste holding tanks and obviates the problems of the prior art.
It is a further object of the present invention to provide a novel odor scrubber and method for precipitating a metal sulfide in water which contains hydrogen sulfide or a mercaptan in which the scrubber has a sacrificial first metal anode and cathode of a second metal more noble than the first metal which are suspended into the water to form an electrolysis cell in which the anode forms an oxide which reacts with sulfur from the hydrogen sulfide or mercaptan to form a sulfide precipitate.
It is yet a further object of the present invention to provide a novel odor scrubber for precipitating a metal sulfide in water which contains hydrogen sulfide or a mercaptan in which the scrubber has a sacrificial metal anode and stainless steel cathode which are suspended into the water to form an electrolysis cell, and in which the anode and cathode are coplanar and suspended in the water with a float which facilitates contact of the water with the anode.
It is still a further object of the present invention to provide a novel floating odor scrubber with a sacrificial metal anode and stainless steel cathode which are coplanar and suspended in the water with a float which may make the scrubber either positively buoyant, with the float on the water surface and the anode and cathode therebeneath, or neutrally buoyant, with the anode and cathode suspended with the float beneath the surface of the water.
It is another object of the present invention to provide a novel scrubber for precipitating a metal sulfide in a waste disposal tube which has standing water therein, the scrubber having a sacrificial anode which is a first metal rod and a cathode which is a second metal rod more noble than a first metal and in which the anode and the cathode are twisted to form a twisted wire pair in which the anode and cathode are in physical and electrical contact to form an electrolysis cell in which the wire pair has an external diameter not substantially greater than a total of diameters of the anode and cathode so as to be free of obstructions to waste disposed through the tube.
These and other objects and advantages of the present invention will be apparent to those of skill in the art from a perusal hereof.